One problem related to automatic transmission cooler has been reported for the 2000 Toyota Tundra. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2000 Toyota Tundra based on all problems reported for the 2000 Tundra.
Truck failed annual inspection due to extreme rust of frame and cross members to the point of frame perforation and imminent failure. Frame directly under driver's seat rusted through where it joins the cross member under the transmission. Frame in front of passenger rear tire extremely rusted where it joins the cross member. The inspector stated this was a more imminent concern than the rusted through portion under the driver because it had a good chance of breaking with the next pothole. Leaf springs for drivers rear tire also extremely rusted. Rear differential housing rusted through on the top with oil leaking out. Exhaust heat shields and hangers rusted away completely. There was no mention of the rear cross member over the spare tire or the gas tank straps being an issue. They could be but were not the imminent concern at this point. I had just replaced the radiator/transmission cooler due to rusting through and anti-freeze entering the transmission and transmission fluid in the cooling system. There were other issues that are apparently common with the Tundra - leaking/cracked manifolds, etc. The truck is at the local dealer pending repair. Technician stated it was the worst case of undercarriage rust he had seen.